This application is a continuation of international application No. PCT/GB87/00200, filed Mar. 23, 1987, which, in turn, claimed the priority of United Kingdom application Ser. No. 8607352, filed Mar. 25, 1986.
1. Field of the Invention
This invention relates to wideband horn antennas.
2. Description of Related Art
One conventional hybrid mode horn consists of a circular horn with a series of internal annular `teeth` or ridges. Such a corrugated horn has limited bandwidth owing to the conditions under which the HE11 hybrid mode is formed.
Other horn antennas have been proposed, for example in German DPS 936400 and DOS 1591747, in which a dielectric rod is incorporated in a horn in an attempt to provide a suitable beam. It was not however, realised or even contemplated, in these proposals that only with a particular narrow set of design conditions can wideband operation be achieved to any satisfactory extent.